Disposable syringe



Feb. 28, 1961 G. K. BURKE 2,972,991

DISPOSABLE SYRINGE Filed Oct. 1, 1958 2 Sheets-Sheet 1 5 v\\\\ 86 I 4 QIN VEN TOR.

GeorqaKBurke BY J 9' Feb 28, 1961 G. K. BURKE DISPOSABLE SYRINGEJNVENTOR. George K. Burke BY MzrW 2 Sheets-Sheet 2 Filed 00 l, 1958nrsrosnnrn SYRINGE George K. Burke, Bethlehem, Pa., assignor to BurronMedical Products, inc, Bethlehem, Pa., a corporation of PennsylvaniaFiled Oct. 1, 1958, Ser. No. 764,657

12 Claims. (Cl. 128-218) The present invention relates to a new andnovel disposable syringe, and more particularly to a hypodermic syringewhich is adapted to be used one time and then discarded.

It has been common practice for many years to employ relativelyexpensive hypodermic syringes and reprocessing or sterilizing theneedles and syringes for subsequent use. It is a primary purpose of thepresent invention to eliminate the use of conventional hypodermicsyringes and avoiding the numerous disadvantages which have prevailed inthe usage of this type of apparatus for many years.

The syringe according to the present invention is a completelydisposable unit. The syringe is initially sterilized as by gas or thelike and sealed in a suitable package such as transparent plastic. Thecomponents of the syringe itself are mainly plastic, the needle employedtherewith being of conventional metallic construction. When it isdesired to make a hypodermic injection, the package within which thesterilized unit is contained is opened, and the invention syringe isutilized for administering a dosage of suitable medicament. After thissingle use of the apparatus, the entire device may be discarded. Thismode of operation is practical in the present case due to the fact thatthe construction, according to the present invention, is extremelysimple and inexpensive in contrast to the hypodermic syringes which havebeen previously employed in the art. Accordingly, it is economicallyfeasible to employ a new syringe for each injection, and as a matter offact, the employment of separate units according to the presentinvention is actually cheaper than employing prior art type syringes andneedles which must be constantly re-processed in order to givesubsequent injections. The re-processing and sterilizing equipmentemployed in the art is in itself quite expensive, and the operation andmaintenance thereof provide an additional expense such that the totalcost involved is greater than that when employing the disposablesyringes of the present invention.

The initial cost of this novel disposable syringe is, of course, muchlower than the initial cost of conventional syringes, and theelimination of re-processing results in a substantial saving for themedicament-injection process as a whole. The employment of such adisposable syringe enables each syringe to be sterile and ready for useat all times, and yet the technique in operating the syringe is the sameas with conventional syringes. The fact that the syringe is disposablealso saves valuable time for hospital personnel and the one-time use ofthe scientifically'sharpened needles assures maximum comfort for thepatient. In addition, the one-time use of the syringe eliminates thedanger of cross contamination and infection which often occurs whenspringes are used in connection with patients having communicablediseases.

An object of the present invention is the pro-vision of a new and noveldisposable syringe which is adapted to be used one time and thendiscarded.

Another object of the present invention is to provide 2,972,991 PatentedFeb. 28, 1961 a disposable syringe which saves the time of the operator,is quite convenient to use and provides maximum comfort for the patient.

A further object of the invention is to provide a disposable syringewhich eliminates the danger of cross contamination and which provides adosage indicator which is very easy to read.

Yet another object of the invention is to provide a disposable syringewherein the aspirated air is efliciently filtered and wherein a safetyseal is provided until the plunger is withdrawn from the barrel.

A still further object of the invention is to provide a disposablesyringe wherein a portion of the springe body is adapted to be brokenoif within the attached needle for preventing re-use of the apparatus.

Yet another object of the present invention is to provide a disposablesyringe which may be quickly and easily assembled during manufacture.

A still further object of the present invention is to provide adisposable syringe which provides a solid seat for the plunger andinsures complete aspiration during operation.

Other objects and many attendant advantages of the invention will becomemore apparent when considered in connection with the accompanyingspecification and drawings wherein:

Fig. 1 is a perspective view of the disposable syringe according to thepresent invention.

Fig. 2 is an exploded perspective view of the disposable springe;

Fig. 3 is a longitudinal section of the assembled syringe;

Fig. 4 is an enlarged longitudinal section, partly broken away, of thebarrel of the apparatus;

Fig. 5 is an enlarged longitudinal section, partly broken away, of theplunger;

Fig. 6 is an end view of the plunger shown in Fig. 5;

Fig. 7 is an end view of the resilient plunger ring of the device;

Fig. 8 is an elevation of the pin member; and

Fig. 9 is an enlarged longitudinal section, partly broken away, of theneedle guard of the device.

Referring now to the drawings wherein like reference charactersdesignate corresponding parts throughout the several views, there isshown in Fig. 1 a disposable syringe according to the present inventionindicated generally by reference numeral 10 and including a barrelmember 11, a plunger member 12, a hypodermic needle 13 and a needleguard 14. The barrel member 11 is preferably formed of transparentplastic material, such as polyethylene, and a plurality of calibrationsor indicia 15 are formed on the surface of the barrel for indicating thedosage.

Referring now to Fig. 4 of the drawings, barrel 11 is seen to have asubstantially cyclindrical hollow configuration, a tapered opening 20being provided at one end portion thereof and a radially extendingflange 21 also being formed at said one end of the barrel terminating ina laterally extending bead 22 for strengthening the outer edge of theflange 21. The fingers of the user are ordinan'ly positioned underflange portion 21 for gripping the barrel when it is desired to. expelthe medicament from the syringe. At the opposite end of the barrel 11, aboss indicated generally by the reference numeral 25 is provided, theboss including an enlarged portion 26 and an integral reduced portion 27having a tapered outer surface 28 which receives a correspondinglytapered surface formed on the inner surface of an opening in the end ofa conventional hypodermic needle. An opening 29 is formed through theboss and communicates with the hollow interior of the barrel. A seat 30is provided at the end of the interior of the barrel, seat 30 having aconvex configuration for a purpose hereinafter more fully described. Itshould also be noted that opening 29 fairs smoothly into seat portion 30through the intermediary of an arcuate portion 31. This smooth roundedportion 31 insures substantially smooth flow of the fluid as it entersinto the interior of the barrel from the opening through the boss,thereby preventing the creation of undesired turbulence.

An additional novel feature of the barrel member lies in the provisionof a substantially annular groove 35 of substantially V-shapedcross-sectional configuration which extends completely around boss 25.It is apparent that groove 35 provides a weakened portion of the endWall of the barrel thereby permitting the end wall to be fractured andthe boss to be removed from the remainder of the barrel.

Referring now to Fig. of the drawings, the plunger according to thepresent invention is also preferably formed of a suitable plasticsubstance, such as polyethylene, the plunger being substantiallycylindrical and of hollow configuration. Plunged 12 has a reduced endportion 40 formed at one end thereof, an'opening 41 being formed throughend portion 49 and in communication With the hollow interior of theplunger. The opposite end portion of the plunger is open and is providedwith a radially extending flange 45 having a substantially concavedepression 46 formed in the upper surface thereof. Depression 46 is ofsubstantial dimension and is adapted to receive the thumb of an operatorduring normal operation.

Referring now to Fig. 6 of the drawings, the outer surface of reducedend portion 40 is of irregular shape, and in this case is shown ashaving four substantially equal flat sides 40', opening 41 formedthrough the boss being substantially cylindrical in configuration. Fourspaced ribs 47 extend downwardly from the undersurface of flange 45along the outer surface of the plunger.

Referring again to Fig. 5 of the drawings, a substantially annularV-shaped rib 50 extends circumferentially about the outer surface ofplunger 12 at a point remote from the reduced end portion thereof. RibSt) is adapted to engage the inner surface of the barrel when the deviceis initially assembled, and maintains a sterile seal between the plungerand the barrel after the syringe has been removed from its protectivepackage, this sterile seal being maintained until the plunger iswithdrawn from the barrel.

Referring now to Fig. 3 of the drawings, a resilient plunger ring 55 ismounted about the reduced end portion of the plunger, and is providedwith a first annular radially extending rib 56 having a flat radiallyoutward surface and two similar spaced annular ribs 57 having roundedradially outward surfaces. These ribs 56 and 57 provide an eflicientseal between the end of the plunger and the barrel during operation ofthe device. As seen most clearly in Fig. 7, one surface 58 of the ringis provided with a substantially square-shaped recess 59, and acylindrical opening 60 is formed through the remainder of the ring andcommunicates with the recess 59. Recess 59 is complementary to thereduced end portion of the plunger, and the reduced end portion of theplunger is received within the recess in the plunger ring such that theplunger ring is mounted on the end of the plunger and relative rotationtherebetween is prevented.

In order to securely lock the plunger ring on the end of the plunger, apin member indicated generally by reference numeral 65 is seen mostclearly in Fig. 8 and comprises a substantially cylindrical shankportion 66 having an enlarged head portion 67 formed at one end thereof,head portion 67 having a substantially frustoconical outer surface 68and defining an annular shoulder 69. A flattened enlarged head portion70 is formed at the opposite end of the pin member and has an annular 4shoulder 71 formed by the undersurface thereof. The outer end surface 72of flattened head portion 70 is of convex configuration complementary tothe convex configuration of seat portion 30 of the barrel, whereby thehead of the pin is adapted to seat firmly and snugly within seat portion30.

When the resilient ring is assembled upon the plunger, the square recessof the ring is first mounted upon the square reduced end portion of theplunger and then pin 65 is forced through the aligned openings in theresilient ring and the plunger, the frusto-conical surface 68 of theenlarged head 67 being slightly deformed as it passes through theseopenings and then snapping into place behind surface 75 Within theplunger such that shoulder 69 prevents withdrawal of the pin from theplunger. The pin is also preferably formed of plastic or similar pliablematerial such that it is adapted to be slightly deformed. The dimensionsof the shank portion 66 of the pin are such that when shoulder 69 of thepin engages surface 75 of the plunger, shoulder 71 of the flattened headof the pin will slightly compress resilient ring 55 so that the ribs 56and 57 thereof will be forced radially outward into engagement with theinner surface of the barrel, thereby effecting a very tight seal betweenthe end of the plunger means and the interior of the barrel.

As seen in Fig. 3, the hypodermic needle 13 is shown in mounted positionupon the boss of the barrel, the hypodermic needle being surrounded andprotected by the needle guard 14. Hypodermic needle 13 is of aconventional construction including an enlarged hub having a bore formedtherethrough and communicating with the interior of an elongated hollowneedle portion having a sharpened point at the outer end thereof. Asseen most clearly in Fig. 9 of the drawings, the needle guard 14comprises an elongated hollow member preferably formed of plastic or thelike, the portion of the needle guard tapering slightly downward to aclosed end portion 81, the opposite end portion 82 thereof being openfor mounting the needle guard on the boss of the barrel. Four equallyspaced ribs 83 similar to the ribs 47 of the plunger are provided on theouter surface of the needle guard. An annular inwardly projecting rib 85is provided adjacent the open end of the needle guard, rib 85 definingan inner diameter slightly less than that of the enlarged portion 26 ofthe boss for firmly mounting the needle guard upon the boss of thebarrel.

A tapered seat 36 is also provided on the inner surface of the needleguard which is adapted to engage a portion of the hypodermic needle forsupporting the hypodermic needle in proper operative position therein.

Formed centrally through the closed end 81 of the needle guard is anopening 87 which permits the aspiration of air into the needle guard. Asseen most clearly in Fig. 3, a body of filter material 88 is disposedwithin the end of the needle guard adjacent opening 87, the filtermaterial being of a suitable substance such as cotton or the like. Aninwardly projecting annular rib 89 is provided adjacent opening 87 formaintaining the filter material in proper operative position. Theapparatus normally will be provided in assembled position within apackage with the flattened head of pin 65 seated in the cooperating seatprovided in the barrel. When it is de sired to utilize the device, thesyringe is removed from its protective package and while holding thebarrel, the plunger is twisted and Withdrawn from the barrel, therebyaspirating air through the filter in the end of the needle guard. Inthis manner, all the air drawn into the barrel during such operation isfiltered thereby substantially reducing the possibility of such airbeing contaminated. Rib 50 on the exterior of the plunger maintains asterile seal with the barrel even after the syringe is removed from itsprotective package until the plunger is withdrawn from the barrel. Theneedle guard is then removed from surrounding relationship with respectto the needle. The needle is then placed in a suitable medicament vialand the filtered air is expelled within the vial. It is apparent thatthe insertion of the filtered air within the medicament vial is farsuperior to the insertion of contaminated air within the medicamentsince this has a tendency to produce undesired production of bacteria inthe medicine. The plunger is then again withdrawn from the barrel todraw medicament upwardly through the hypodermic needle and into theinterior of the barrel. The dosage may be quickly and easily read by0bserving the position of the flattened head of the pin mounted at theend of the plunger. To facilitate easy reading of the dosage, the pinand resilient ring are preferably of different colors so as to be morereadily discernible. The device may then be employed in a conventionalmanner for administering a dosage of medicine.

Subsequent to use, the needle may be removed from the syringe if desiredsimply by turning it with respect to the syringe, or if it is desired tocompletely discard the apparatus and to destroy the device to preventreuse, the needle guard is replaced on the boss and grasped about theupper rib portion thereof and bent with respect to the barrel to snapoff the boss portion around the weakened portion defined by groove 35.This completely destroys the effectiveness of the barrel and will causethe jagged boss portion to be locked within the end of the needle.Except for the needle, the remaining components of the device arepreferably of plastic with the exception of the resilient plunger ring55 which may be preferably formed of rubber or other suitable resilientmaterial. The components other than the needle may accordingly becompletely incinerated to destroy them, and the needle may be disposedof in any desired manner.

It is apparent from the foregoing that there is provided a new and noveldisposable syringe which is very convenient to use and which saves timein operation and provides maximum comfort for the patient. The deviceprevents the danger of cross contamination, and the dosage is very easyto read. A safety seal is provided between the plunger and the barreluntil the plunger is removed from the barrel and the aspirated airwithin the device is filtered to thereby reduce the possibility ofcontamination of medicaments stored in vials. The apparatus includes aportion which is adapted to break off to prevent subsequent re-use ofthe device, and it is apparent that the entire assembly may be quicklyand easily assembled during manufacture. A seat is provided within thebarrel such that the end of the plunger is snugly and firmly seated and,furthermore, complete as piration is insured by this rounded seatportion. Additionally, smooth flow of fluid within the device is assuredby the provision of a snugly secured surface between the opening in theboss of the device and the seat portion of the barrel. The device isquite simple and inexpensive in construction, and yet is very efficientand reliable in operation.

As this invention may be embodied in several forms Without departingfrom the spirit or essential characteristics thereof, the presentembodiment is therefore illustrative and not restrictive, and since thescope of the invention is defined by the appended claims, all changesthat fall within the metes and bounds of the claims or that form theirfunctional as well as conjointly cooperative equivalents are thereforeintended to be embraced by those claims.

I claim:

1. A disposable syringe which comprises a generally cylindrical hollowbarrel, a substantially cylindrical hollow plunger slidably positionedwithin said barrel, said plunger having a reduced end portion having anirregular outer surface, a resilient plunger ring having a plurality ofsubstantially annular rings formed on the outer surface thereof, saidring having formed in one surface thereof an irregular recesscomplementary to the irregular configuration of said reduced end portionand preventing relative rotation between said plunger and said plungerring, said plunger ring also having another opening formed in theopposite surface thereof and in communication with said recess, saidreduced end portion having an opening formed therethrough incommunication with the hollow interior of said plunger, and pin meansextending through the opening in said ring and the opening in saidreduced end portion for securing said resilient plunger ring to saidplunger.

2. Apparatus as defined in claim 1 including a shoulder formed on theinterior of said hollow plunger, said pin having an elongate shankportion extending through said openings, a tapered head portion formedat one end of said shank portion and defining an annular shouldercooperating with the shoulder in said plunger for retaining the pinpermanently in operative position, and an enlarged head portion formedat the opposite end of said shank and engaging said plunger ring forcompressing the plunger ring between said last mentioned head portionand said plunger.

3. Apparatus as defined in claim 2 wherein said last mentioned headportion of the pin' has an outer end portion of arcuate configuration,said barrel having a seat portion formed at one end of the hollowinterior thereof, said seat portion having an arcuate configurationcomplementary to that of the arcuate end portion of said last mentionedhead portion.

4. Apparatus as defined in claim 1 including a circumferentiallyextending rib formed on the outer surface of said plunger at a pointremote from said reduced end portion for engaging the inner surface ofsaid barrel to provide a sterile seal therewith.

5. Apparatus as defined in claim 1 wherein said plunger has an enlargedradially extending end portion at the end opposite said reduced endportion, said enlarged end portion having a depression formed in theouter end thereof for receiving the thumb or finger of an operator.

6. A disposable syringe comprising a substantially cylindrical hollowtransparent barrel, one end portion of said barrel being opened and theopposite end portion of said barrel including a longitudinallyprojecting boss connected to the cylindrical wall of the barrel by anannular wall portion, said annular Wall portion including means forweakening said wall portion whereby said wall portion may be easilybroken to separate the boss from the barrel, a plunger slidably mountedwithin said barrel, means mounted on one end of said plunger for sealingsaid plunger with respect to said barrel, and means on the outer surfaceof said plunger at a point remote from said last mentioned means forsealing said plunger with respect to said barrel.

7. Apparatus as defined in claim 6 wherein said means for sealing saidone end of the plunger with respect to the barrel includes a resilientplunger ring mounted upon the end of the barrel and having a pluralityof spaced annular ribs formed on the outer surface thereof, and pinmeans connected to said plunger and engagaing said plunger ring forcompressing and expelling the plunger ring in a radial direction andsecuring the plunger ring permanently in operative position.

8. Apparatus as defined in claim 7 wherein said pin means has anenlarged head at one end thereof, said head having an outer convexsurface, the interior of said barrel having a seat formed at one endthereof having a corresponding convex configuration for snugly receivingthe convex surface of said head.

9. A disposable syringe comprising a substantially cylindrical hollowtransparent barrel having an open end and a surrounding flange formedthereat, the opposite end of said barrel including an end wall having alongitudinally projecting boss formed integral therewith, said bosshaving an opening formed therethrough in communication with the hollowinterior of said barrel, a hollow substantially cylindrical plungerslidably mounted in said barrel, a resilient plunger ring mounted at oneend of said plunger, means preventing relative rotation between saidplunger ring and said plunger, pin means securing said plunger ring inoperative position, means for sealing said plunger with respect to saidbarrel at a point remote from said plunger ring, the end wall of saidbarrel having a weakened portion for facilitating fracture if the endwall and removal of the boss, said boss being adapted to receive ahypodermic needle, an elongated hollow needle guard having an open endportion mounted on said boss, the opposite end portion of said needleguard being closed and having an opening formed therethrough, and filtermeans disposed within said needle guard adjacent the opening in theclosed end thereof for filtering air aspirated into said filter guard.

10. Apparatus as defined in claim 9 including indicia formed on saidbarrel, said pin means having a flattened head portion formed on theouter end thereof, said head portion and said plunger ring being ofdifierent colors for permitting instant direct reading of dosage.

11. Apparatus as defined in claim 9 wherein said pin means has aflattened head formed at the outer end thereof, said head having aconvex outer surface, the end wall of said barrel having a complementaryconvex surface formed therein for receiving the convex surface of saidhead, said opening through the boss fairing snugly into said convexsurface.

12. A disposable syringe which comprises a hollow barrel, a plungerslidably disposed within said barrel, a resilient plunger ring mountedaround one end of said plunger, and a pin member attached to saidplunger for securing said plunger ring in operative position, said oneend of the plunger being of reduced size, said plunger being hollow,said one end of the plunger having an opening formed therethrough incommunication with the hollow interior of the plunger, the hollowinterior of said plunger defining a shoulder, said pin member havingenlarged head portions at opposite ends thereof, one of said headportions engaging said shoulder, and the other of said head portionsengaging said plunger ring.

References Cited in the file of this patent UNITED STATES PATENTS814,543 Horner Mar. 6, 1906 1,540,126 Hein June 2, 1925 2,020,828Goldberg Nov. 12, 1935 2,578,394 Blackman Dec. 11, 1951 2,675,804 KrugApr. 20, 1954 2,828,742 Ashkenaz Apr. 1, 1958 2,860,635 Wilburn Nov. 18,1958

